Cluster synthesis. 41. New platinum-ruthenium cluster complexes from

Nov 2, 1992 - New Platinum-Ruthenium Cluster. Complexes from the Reaction of PhC=CPh with. Pt2Ru4(CO)i8. Synthesis and Structural Characterizations...
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Organometallics 1993,12, 1248-1256

1248

Cluster Synthesis. 41. New Platinum-Ruthenium Cluster Complexes from the Reaction of PhC-CPh with Pt&u4(CO)18. Synthesis and Structural Characterizations of Pt2Ru3(CO)8( p3-q2-PhC2Ph)2( p4-q2-PhC2Ph)9 Pt3Ru6(CO)14(p3-V2-PhC2Ph) 3, Pt2 R ~(4CO) 14( p3-q2-PhC2Ph)(pd-q2-PhC2Ph)9 PtsRus(co)18(p3-q~-PhCzPh)3, and PtRu2(CO)6( p3-q2-PhC2Ph)(dppe) Richard D. Adams' and Wengan Wu Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208 Received November 2, 1992

The reaction of PtzRur(C0)la (1) with diphenylacetylene, PhCzPh, in refluxing heptane (97 "C) yielded two new compounds, Pt2Ru:,(CO)~(~~3-1~-PhC2Ph)2014-11~-PhC2Ph) (2,67'% ) and Pt3R Q ( C O ) ~ ~ ( ~ ~ - + P (3,27%). ~ C ~ P ~ Both ) ~ compounds 2 and 3 were characterized by IR, proton NMR,and single-crystal X-ray diffraction analyses. Compound 2 contains five metal atoms, two platinum and three ruthenium, which are arranged in a distorted square-pyramidal structure. Compound 3 consists of a six-metal Pt3Ru3 octahedral cluster that is capped by three ruthenium atoms. There is a Ru-Ru bond between two of the capping ruthenium atoms. When 3 was treated with CO a t 25 "C, two new compounds, Pt~Ry(CO)14(/1.3-o~-PhCzPh)(114-11~-PhC2Ph) (4, 16%) and Pt3R~(CO)la(r3-'rl~-PhC2Ph)3 (5,20%)) were obtained. Compound 4 consists of a square-pyramidal Pt2Ru3 cluster that has a ruthenium group bridging the Pt-Pt axial-basal edge. Compound 5 exhibits anovel cluster that has a central triplatinum cluster with diruthenium groupings bridging each Pt-Pt edge and a triply bridging alkyne on each PtRu2 triangle. The molecule could be viewed as an assembly derived of three PtRu2(CO)6(113-t12-PhC2Ph) groupings. Compound 5 was converted back to 3 (94% ) by heating in a hexane solution. Upon reaction with 192-bis(diphenylphosphino)ethane(dppe),it was converted into 3 equiv of the new complex PtRu2(C0)6(r3-'r12-PhC2Ph)(dppe)(6)in 10% yield. When compound 5 was treated with CO prior to the addition of dppe, compound 6 was obtained in a much better yield (46% ). Crystal data for 2: space group P1,a = 13.219(3) A, b = 13.262(3) A, c = 13.126(3) A, a = 102.75(2)", j3 = 96.69(2)",y = 85.59(2)*,2 = 2,3659reflections, R = 0.024. Crystal data for 3: space group Pi, a = 15.218(2)A, b = 15.444(3)A, c = 14.464(3)A, a = 94.48(2)",j3 = 100.29(1)0,y = 87.55(2)", 2 = 2,4722 reflections, R = 0.040. Crystal data for 4: space group P21/c, a = 16.381(2) A, b = 10.715(2) A, c = 23.987(2) A, j3 = 90.215(7)",2 = 4,3179reflections, R = 0.022. Crystal data for 5: space group PI,a = 14.866(2) A, b = 17.507(5) A, c = 13.597(3) A, a = 102.50(2)",/3 = 93.31(1)",y = 100.86(2)",2 = 2,4943reflections, R = 0.033. Crystal data for 6: space group Pbcn, a = 23.103(2) A, b = 21.930(4) A, c = 20.663(2) A, 2 = 8,3721 reflections, R = 0.042.

Introduction Studies of coordination and reactivity of alkynes in transition metal cluster complexes have been of interest because it is believed that these small molecules may serve as models for understandingsome aspects of the adsorption and reactivity of small molecules on metal We have recently reported that synthesis and structural characterization of the new platinum-ruthenium carbonyl cluster complex PtzRu4(CO)l~(l).3We have found that

1 readily reacts with a variety of small molecules: hydrogen? 1,Bcyclooctadiene (COD),6l,Bbis(diphenylphosphinolethane (dppe),3b and even other metal carbonyl complexes6 to produce interesting new platinum-ruthenium cluster complexes. Compound 1 has a open puckered raft structure which can be viewed as a dimer of the unknown species [PtRuz(CO)sl. Our investigations have shown that 1 can be symmetrically split to form a PtRu2 trinuclear cluster (e.g. PtRuz(CO)a(dppe))or condensed to form higher nuclearity species derived from the combination of three PtRu2 groupings (e.g. Pt3Rus(CO)zl(rH ) ~ ( P ~ - H )We ) . ~have now expanded our studies of 1 to include the reaction with diphenylacetylene, PhC2Ph. The principal product is the compound Pt3Rus(C0)14(r3-a2-

(1) (a) Sappa, E.; Tiripicchio, A.; Braunstein, P. Chem. Reu. 1983,83, 203. (b) Raithby, P. R.; Rosales, M. J. Adu. Znorg. Chem. Radiochem. 1985, 29, 169. (c) Osella, D.; Raithby, P. R. In Stereochemistry of Organometallic and Inorganic Compounds; Bernal, I., Ed.;Amsterdam: Elsevier, 1989 Vol. 3. (2) (a) Muetterties, E. L.; Rhodin, T. N.; Band, E.; Brucker, C. F.; (4) Adams, R. D.; Li, Z.; Swepston, P.;Wu, W.; Yamamoto, J. J.Am. Chem. Soc. 1992,114, 10657. Pretzer, W. R. Chem. Reu. 1979, 79,91. (b) Albert, M. R.; Yates, J. T., Jr. The SurfaceScientist'sGuide t o Organometallic Chemistry;American (5) Adams. R. D.: Alexander, M. S.; Arafa, I.: Wu, W. Inorg. Chem. Chemical Society: Washington, D.C.; 1987. 1991,30,4717. (6) Adams, R. D.; Li, Z.; Lii, J.-C.; Wu, W. Organometallics 1992,11, (3) (a) Adams, R. D.; Chen. G.; Wang, J.-G.;Wu, W. Organometallics 1990,9,1339. (b)Adams,R.D.;Chen,G.;Wu,W.J.ClusterSci.,inpress. 4001.

0 1993 American Chemical Society

Organometallics, Vol. 12, No. 4, 1993 1249

Cluster Synthesis

Table I. Crystal Data of Compounds 2-6 2

3

5

4

6

formula

Pt2R~4014CaH20

Pt3RU6018C6oH30

formula weight crystal system lattice parameters

1543.07 monoclinic

2230.58 triclinic

PtRU~P206C46Hw CH~CO~C~H~*O.SC~HI~ 1280.16 orthorhombic

16.38 1(2) 10.715(2) 23.987 (2) 90.0 90.215(7) 90.0 4210(1) PZl/c(no. 14) 4 2.43 81.29 20 40.0 3179 0.022; 0.023

14.866(2) 17.507(5) 13.597(3) 102.50(2) 93.31(1) 100.86(2) 3375(1) Pi(no. 2) 2 2.19 75.99 20 40.1 4943 0.033; 0.049

23.103(2) 21.930(4) 20.663(2) 90.0 90.0 90.0 10469(4) Pbcn(no. 60) 8 1.62 33.62 20 41.0 3721 0.042; 0.051

a (A)

(A) c (A) b

a (deg)

P (deg) Y (ded

v (A')

space group Z value pcalc(g/cm3) p (Mo Ka) cm-I) temperature ("C) 2emax( 0 ) no. obs (I > 30.) residuals: R, R ,

13.219(2) 13.262(3) 13.126( 3) 102.75(2) 96.69(2) 85.59( 2) 2226(1) Pi(no. 2) 2 2.17 73.58 20 40.0 3659 0.024; 0.029

15.2 18(2) 15.444(3) 14.464(3) 94.48(2) 100.29( 1) 87.55 (2) 3333 (2) Pi(no. 2) 2 2.24 76.91 23 42.0 4722 0.040; 0.040

hexane) for 2: 2063 (m), 2038 (m), 2025 (vs), 2010, (s), 1988 (m), 1976 (m), 1965 (w). IR (uC0 in hexane) for 3: 2058 (m), 2040 (vs), 2024 (s),2018 (s),2001 (s),1979(w), 1970(w), 1962 (w), 1944 (vw), 1897 (vw, Br), 1886 (sh). IR for unknown purple compound 2063 (m), 2019 (vs), 1988 (w), 1970 (m), 1963 (m); for unknown brown compound: 2049 (81,2041(vs), 2033 (s) 2023(s), 2014 (m), 2007 (s), 1986 (w). 1H NMR (6 in CDC13) for 2: 6.7-7.5 (m, Ph). 1H NMR (6 in CDC13) for 3: 6.2-8.0 (m, Ph). Anal. Calcd (found) for 2: C, 41.36 (41.66);H, 2.08 (1.81). Anal. Calcd (found) for 3: C, 31.75 (32.68); H, 1.43 (1.88). PhCzPh)g, 3. Its formula suggests that it is also derived Reaction of 3 with CO. 3 (15.9 mg, 0.0075 mmol) was from the combination of three PtRuz(p3-s2-PhCzPh) dissolved in 25 mL of hexane, and CO was purged through the groupings. Compound 3 adds CO to yield two products: solution slowly at 25 "C for 15 min. The solvent was removed the smaller cluster PtR~4(C0)14(p3-9~-PhC~Ph)(p4-s~by rotary evaporation, and the residue was separated by TLC PhCzPh) (4) andamore openedformof 3,Pt3Ru&0)&3plates using a CHzClz/hexane(1/4) solvent mixture. This yielded sZ-PhCzPh)3(5). Compound 5 reacts with dppe to yield in order of elution: 2.8 mg of PtzRu4(CO)14(p~g-g~-PhCzPh)(~~the expected trinuclear grouping PtRuz(p3-q2-PhCzPh)in +PhC,Ph) (4,16% ), 3.6 mg of Pt3R~s(CO)ls(p3-11~-PhC~Ph)3 (5, (dppe) (6). the isolablecomplex P~Ruz(CO)G(~~-~~-P~CZP~) 20%),and 6.0 mg of a brown compound X. Numerous attempts A portion of this work has been previously published.3a to obtain crystals of compound X were unsuccessful. IR (uC0, cm-l in hexane) for 4: 2085 (w), 2059 (vs), 2044 (s), 2025 (m), 1996 (sh), 1993 (w), 1986 (w). IR (uC0, cm-l in hexane) for 5: Experimental Section 2080 (m), 2066 (s), 2057 (vs), 2052 (vs), 2040 (s), 2012 (m), 2004 General Procedures. Reactions were performed under a dry (m),1999 (m),1991(m), 1978 (w);for X: 2065 (w), 2049 (m), 2040 nitrogen atmosphere. Reagent-grade solvents were dried over (sh), 2034 (s), 2024 (vs), 2008 (m), 2001 (m), 1990 (w), 1984 (w), molecular sieves and were deoxygenatedby purging with nitrogen 1961 (vw), 1952 (vw). lH NMR (6 in CDC13) for 4: 7.1-7.7 (m, prior to use. IR spectra were recorded on a Nicolet 5DXB FT-IR Ph). lH NMR (6 in CDC13)for 5: 7.1-7.6 (m, Ph). Anal. Calcd (found) ford: C, 32.69 (32.74);H,1.31(1.27). Anal. Calcd (found) spectrophotometer. A Bruker AM-300 FT-NMR spectrometer was used to obtain lH NMR spectra. Elemental microanalyses for 5: C, 32.31 (32.52); H, 1.36 (1.18). were performed by Desert Analytics, Tucson, AZ. TLC sepaReaction of X with CO. X (7.0 mg) was allowed to react with rations were performed by using silica gel (60 A, f254) on plates CO (1atm) in 20 mL of hexane at 25 OC for 45 min. The solvent (Whatman 0.25 mm). P ~ ~ R u ~ ( Cand O ) PtRuz(C0)ddppe) ~B were was removed on arotary evaporator,and the residue was separated prepared by previously reported procedure^.^ PhCzPh and 1,2by TLC. This yielded 0.8 mg of 4, 1.4 mg of 5, and 3.6 mg of bis(dipheny1phosphino)ethane (dppe) were purchased from unreacted X. Aldrich and were used without further purification. Reaction of X with CO and dppe in Two Steps. X (6.5 mg) Reactionof PtzRud(C0)ls(1) WithDiphenylacetylene. In was dissolved in 20 mL of hexane, and CO was allowed to purge a typical reaction, a 30.0-mg amount of 1 (0.023 mmol) and 10.0 through this solution slowly at 25 OC for 60 min. A 3.0-mg sample mg of PhCzPh (0.056mmol) were dissolved in 40 mL of heptane of dppe was then added to the resulting solution, and the mixture at 40-50 OC. The solution was then heated to reflux (97 "C) for was stirred for an additional 50 min; 3.6 mg of 6 was isolated by 10 min. After cooling to 25 "C, the solvent was removed on a TLC. rotary evaporator and the residue was separated by TLC. The Pyrolysis of 5 at 68 "C. An 8.5-mg amount of 5 (0.0040) following products were separated in order of elution by using mmol) dissolved in 20 mL of hexane was heated to reflux under a CHzClz/hexane(3/7) solvent mixture: a trace amount of RUBa slow purge of nitrogen for 30 min. The color of the solution (C0)lz; a trace amount of unreacted 1; 0.6 mg of RQ(C0)12(p4changed from brown to green during this time. The solvent was +-PhCzPh),7 3 % ; 2.1 mg of PtzR~3(CO)s(~~-?2-PhC~Ph)~(p4-~2removed by rotary evaporation, and the product was separated PhC2Ph)(2,6%);8.7mgofPt3R~&O)~4(p~-~~-PhC2Ph)~ (3,27%); by TLC to yield 7.6 mg of 3, 94%. 2.2 mg of an unknown purple compound; and 3.3 mg of an Reaction of 5 with CO. An 8.4-mgamount of 5 (0.0037mmol) unknown brown compound. All attempts to obtain crystals of in 20 mL of hexane was allowed to react with CO (1atm) at 25 the latter two compounds have been unsuccessful. IR (uC0 in "C for 1 h. At this time, the IR spectrum showed absorptions at 2101 (w), 2073 (m), 2057 (vs), 2042 (m), 2024 (sh), 2019 (m), (7) Bruce, M. I.; Shaw, G.; Stone, F. G. A. J . Chem. SOC.,Dalton Trans. 2008 (w), 2001 (m), 1993 (w), 1978 (w) that we attribute these to 1972, 1781.

A d a m and

1250 Organometallics, Vol. 12, No. 4, 1993 Table V. atom 0.22008(03) 0.39940(03) 0.20037(06) 0.10343(06) 0.3017 l(06) 0.2560(08) 0.1298(07) 0.2988(06) 0.5445(07) -0.0159(06) -0.0567(07) 0.4377(06) 0.1769(05) 0.2228(08) 0.3144(07) 0.1036(07) 0.0470(07) 0.3340(07) 0.4202(07) 0.238 l(08) 0.1582(08) 0.2692(08) 0.4900(09) 0.0278(08) 0.0053(09) 0.3869(08) 0.2099(08)

Y

2

0.08356(03) 0.20572(03) 0.29784(06) 0.17606(06) 0.125 17(06) -0.0442(07) 0.5212(06) 0.3304(06) 0.1757(08) -0.0 176(07) 0.2658(07) 0.1 164(06) -0.0273(06) 0.2818(07) 0.2997(07) 0.1926(07) 0.2366(07) -0.0007(07) 0.0558(06) 0.0040(08) 0.4367(09) 0.3165(07) 0.1877(08) 0.0578(09) 0.23 13(08) 0.1213(07) 0.0400(08)

0.34394(03) 0.35745(03) 0.36250(06) 0.19297(05) 1.17123(06) 0.5108(06) 0.4182(06) 0.5880(06) 0.5419(07) 0.1512(06) 0.0490(07) 0.0012(06) 0.0069(06) 0.1879(07) 0.2551(07) 0.4 105(07) 0.3341(07) 0.2556(07) 0.2627(07) 0.4485(09) 0.3954(07) 0.4997(09) 0.4724(10) 0.1675(07) 0.1042(09) 0.0649(08) 0.0718(08)

2.62(2) 3.07(2) 2.79(3) 2.41(3) 2.61(3) 7.8(5) 6.7(4) 4.9(4) 8.6(6) 6.1(4) 7.0(5) 5.2(4) 4.9(4) 3.1(4) 2.9(4) 2.7(4) 3.1(4) 2.9(4) 2.6(4) 4.3(5) 4.2(5) 3.3(5) 4.7(6) 3.7(5) 4.3(5) 3.5(5) 3.6(5)

Table 111. Intramolecular Distances' for 2 Pt( 1)-Pt(2) Pt( l)-Ru( 1) Pt( l)-Ru(2) Pt( l)-Ru(3) Pt( 1)-c(3) Pt( 1)-c(5) Pt(Z)-Ru( 1) Pt(Z)-Ru( 3) Pt( 2)-C( 2) Pt(2)-C(6) Ru(l)-Ru(2) Ru(l)-C(1) Ru( 1)-C(2) Ru( 1)-C(3)

2.9396(9) 2.793( 1) 2.807(1) 2.797(1) 2.154(9) 2.107(9) 2.8 16(1) 2.666( 1) 2.19(1) 2.116(8) 2.696(1) 2.306(9) 2.1 86(9) 2.198(9)

Ru(l)-C(4) Ru(2)-Ru(3) Ru(2)-C( 1) Ru(2)-C(4) R~(2)-C(32) Ru(3)-C( 1) Ru(3)-C(2) Ru(3)-C( 5) Ru(3)-C(6) C(l)-C(2) C(3)-C(4) C(5)-C(6) M-C(av) 0-C(av)

2.20(1) 2.688(1) 2.21( 1) 2.051(9) 2.58(1) 2.229(9) 2.343(9) 2.189(9) 2.14(1) 1.42(1) 1.39(1) 1.40( 1) 1.88(1) 1.1 5( 1)

Distances are in angstroms. Estimated standard deviations in the least significant figure are given in parentheses.

Table IV. Intramolecular Bond Angles' for 2 Pt(2)-Pt( l)-Ru( 1) Pt(2)-Pt( l)-Ru(2) Pt(2)-Pt( l)-Ru(3) Ru( 1)-Pt( l)-Ru(2) Ru( 1)-Pt( l)-Ru(3) Ru(Z)-Pt( l)-Ru(3) Pt( l)-Pt(Z)-Ru( 1) Pt ( 1)-Pt (2)-R~(3) Ru( l)-Pt(2)-Ru(3) Pt( l)-Ru( 1)-Pt(2)

58.78(3) 95.20(3) 55.32(2) 57.57(3) 73.24(3) 57.32(3) 58.00(3) 59.62(3) 74.86(3) 63.22(3)

Pt(l)-Ru(l)-Ru(2) Pt(2)-Ru( l)-Ru(2) Pt(l)-Ru(2)-Ru(l) Pt( l)-Ru(2)-Ru(3) Ru(l)-Ru(Z)-Ru(3) Pt(l)-R~(3)-Pt(2) Pt(l)-Ru(3)-R~(2) Pt(2)-Ru(3)-R~(2) Ru(3)-C(32)-0(32) M-C(av)-0

61.49(3) 1OO.70(4) 60.94(3) 61.14(3) 76.52(4) 65.06(3) 61.53(3) 104.91(4) 162.4(9) 176(1)

0 Angles are in degrees. Estimated standard deviations in the least significant figure are given in parentheses.

a species that we propose to be PtRuz(CO)e(~3-?2-PhCzPh), 7. This compound was stable only under a CO atmosphere and could not be isolated. After removal of the CO atmosphere and solvent, only compounds 4 (0.6 mg, lo%),2 (2.2 mg, 40%), 5 (2.0 mg), and X (1.1mg) were isolated after separation by TLC. Reaction of 5 with 1,t-Bis(dipheny1phosphino)ethane (dppe). A5.2-mgamountof5 (0.0023mmol)anda2.8-mgamount of dppe (0.0070 mmol) were dissolved in 10 mL of CHzClZ. The solution was stirred at 25 OC for 40 min. The solvent was removed by rotary evaporation, and the residue was separated by TLC using a CHzC12/hexane(3/7) solvent mixture. This yielded 1.2 mg of unreacted 5 (22%),0.6 mg of red PtRuz(C0)6(r3-?2-PhC2Ph)(dppe), 6 (lo%), and traces of a few uncharacterizable

Wu

Positional Parameters and B(eq)Values for PtJR%(CO)dPhCCPhh 3

atom

X

Y

z

Pt( 1) Pt(2) Pt(3) Ru(1) Ru(2) Ru(3) Ru(4) Ru(5) Ru(6) O(1 1) O(12) O(21) O(22) O(31) O(33) O(34) O(41) O(42) O(51) O(52) O(61) O(62) O(63) C(1) C(2) C(3) C(4) C(5) C(6) C(11) C( 12) C(21) C(22) C(31) C(33) C(34) C(41) C(42) C(51) C(52) C(61) C(62) C(63)

0.28983(05) 0.35536(05) 0.10855(05) 0.16444(10) 0.21639(10) 0.25585( 10) 0.19905( 10) 0.14011(11) 0.37638( 11) 0.2257( 10) -0.0271(12) 0.0945(11) 0.1010(10) -0.0835(13) 0.3886(09) 0.1089(10) 0.2579(10) 0.0155(09) -0.0459(11) 0.2095(10) 0.3281(11) 0.5712(11) 0.4294(10) 0.3454(10) 0.2639( 11) 0.2397(11) 0.1515(11) 0.3166(11) 0.3812(11) 0.2051(12) 0.0477( 15) 0.1447(14) 0.1473(13) -0.0087(16) 0.3382(12) 0.1620(14) 0.2335(13) 0.0855( 13) 0.0251(14) 0.1813(13) 0.3467( 15) 0.4970(15) 0.3919(13)

0.23978(05) 0.30192(04) 0.31485(05) 0.33172( 10) 0.19955(09) 0.40892(09) 0.37427(09) 0.15391(09) 0.12352(09) 0.43 12( 10) 0.3622(11) 0.0509(11) 0.2388(09) 0.2756( 11) 0.4838(09) 0.5362( 10) 0.4077( 10) 0.4573(09) 0.0875(10) -0.0207(11) -0.0648(12) 0.0731(10) 0.1080( 10) 0.4339( 10) 0.4808( 10) 0.2 186(1 1) 0.1908(11) 0.1441(1 1) 0.2046(11) 0.3899( 12) 0.35 19( 14) 0.1047( 14) 0.2480( 13) 0.2858( 14) 0.4552( 12) 0.48 19( 14) 0.3968( 12) 0.4253(12) 0.1 134(13) 0.0467( 14) 0.0078( 15) 0.0900( 14) 0.1309( 13)

0.53032(05) 0.70801(05) 0.57947(05) 0.41884( 1) 0.69602( 10) 0.58 198(10) 0.74746( 10) 0.49914( 10) 0.65676( 10) 0.2743( 10) 0.3182( 12) 0.6884(11) 0.8460( 10) 0.5127( 12) 0.4793( 10) 0.51 18(10) 0.9590( 11) 0.7389(09) 0.4664( 1 1) 0.4440( 11) 0.6393( 12) 0.7061( 1 1) 0.4655( 11) 0.7138(11) 0.7188(11) 0.3866( 11) 0.3713( 11) 0.7882( 1 1) 0.7898( 1 1) 0.3299( 13) 0.3562(15) 0.6823( 14) 0.7896( 14) 0.5363(15) 0.51 73( 13) 0.5305( 14) 0.8791(14) 0.7412( 13) 0.4786( 13) 0.4668( 13) 0.6442( 15) 0.6866( 14) 0.5301( 15)

B(eq), A2 3.43(3) 3.20(3) 3.73(3) 3.82(7) 3.65(7) 3.42(7) 3.62(7) 4.1 2(7) 4.04(7) 7.4(4) 9.6(5) 8.6(4) 7.1(4) 9.9(5) 6.7(3) 7.1(4) 8.2(4) 6.5(3) 8.2(4) 8.3(4) 9.4(5) 8.5(4) 8.3(4) 3.2(3) 3.4(4) 3.8(4) 3.7(4) 3.6(4) 3.9(4) 5.0(4) 6.5(5) 6.1(5) 5.5(5) 6.8(6) 4.8(4) 5.9(5) 5.3(5) 4.7(4) 5.4(5) 5.4(5) 6.6(5) 6.2(5) 6.0(5)

products. IR (KO, cm-l in hexane) for 6 2048 (s), 2016 (vs), 1979 (s), 1966 (m), 1949 (m). lH NMR (6 in CH2C12) for 6 7.07.4 (m, Ph, 30 H), 2.2-2.4 (m, CH2,4 H, 2 J p _ = ~ 15.3 Hz). Anal. Calcd (found) for 6: C, 48.55 (48.38); H, 2.66 (2.51). Reaction of 5 with a Combination of CO and dppe. An 8.6-mg amount of 5 (0.004 mmol)was dissolvedin 20 mL of hexane, and CO was purged slowly through the solution at 25 OC for 60 min. A 6.0-mg portion of dppe (0.014 mmol) was then added, and the mixture solution was stirred for an additional 50 min. The solvent was removed by rotary evaporation, and the residue was separated by TLC. This yielded 2.1 mg of unreacted 5 (25% ) and 6.0 mg of 6 (46%). Reaction of PtRuz(CO),(dppe) with PhCzPh. A 13.5-mg amount of PtRu&O)s(dppe) (0.013 mmol) was mixed with 6.0 mg of PhCzPh (0.034 mmol) in 15 mL of heptane. The solution was then heated to reflux (97 OC) for 4 h. The colorof the solution changed from yellow to dark-red. After cooling, the solvent was removed by rotary evaporation and the residue was separated by TLC. This yielded 5.4 mg of 6 (36%) with 1.3 mg of unreacted PtRuz(CO)s(dppe) (10%) recovered. Crystallographic Analysis. Crystals of compound2 suitable for X-ray diffraction analysis were grown by slow evaporation of solvent from a solution of ethyl acetate/ethanol (2/1) at 25 "C. Crystals of compound 3 were grown from a solution in hexane solvent by cooling to 10 OC. Crystals of compound 4 were grown from a solution in a CH&lz/hexane (1/2) solvent mixture by cooling to -20 "C. Crystals of compound 5 were grown from a solution in a CHzC12/hexane(1/1) solvent mixture by cooling to 10 "C. Crystals of compound 6 were grown in a solution of ethyl

Organometallics, Vol. 12, No. 4, 1993 1251

Cluster Synthesis

Table VI. Intramolecular Distances. for 3 Pt(l)-C(3) Pt( 1)-C(63) Pt( l)-Ru(5) Pt( 1)-Ru( 1) Pt ( 1)-Pt (2) Pt( 1)-Ru(3) Pt( l)-Ru(6) Pt( 1)-Ru(2) Pt(2)-C(6) Pt(2)-C( 1) Pt( 2)-Ru( 2) Pt(2)-Ru(4) Pt (2)-Ru( 3) Pt(2)-Ru(6) Pt(3)-Ru( 1) Pt(3)-Ru(4) Pt(3)-Ru(3) Pt(3)-Ru(S) Pt(3)-Ru(2) Ru(l)-Ru(3) Ru(l )-C(3) Ru( 1)-C( 4)

2.09(2) 2.24(2) 2.637(2) 2.699(2) 2.702(1) 2.714(2) 2.785(2) 2.937(2) 1.97(2) 2.03(2) 2.667(2) 2.719(2) 2.760(2) 2.817(2) 2.648(2) 2.685(2) 2.7 16(2) 2.721(2) 2.817(2) 2.73(2) 2.11(2) 2.24(2)

Ru(2)-C(22) RW-C(5) Ru(2)-Ru(4) Ru(2)-Ru(6) Ru(2)-Ru(5) Ru(3)-C( 1) Ru(3)-C(2) Ru(3)-Ru(4) ~u(4)-~(2) Ru(4)-C(22) Ru(5)-C(4) Ru(6)-C(63) Ru(6)-C(6) Ru(6)-C(5) C(l)-C(2) C(3)-C(4) C(5)-C(6) 0-C(av) M-C(av) Pt( 1)-Pt(3) Ru(1)-R~(5)

1,95(2) 2.04(2) 2.757(2) 2.788(2) 2,920(2) 2.15(2) 2.18(2) 2.782(2) 2.06(2) 2.30(2) 2.02(2) 1.90(2) 2.20(2) 2.24(2) 1.42(2) 1.40(2) 1.38(2) 1.16(2) 1.85(2) 3.1 24( 1) 3.125(2)

Table VIII. Positional Parameters and B(eq) Values for ptzR~(C0) idC2Phzh 4 atom X Y Z B(ea). A2

Distanfes are in angstroms. Estimated standard deviations in the least significant figure are given in parentheses.

Table VII. Intramolecular Bond Angles. for 3 Ru(S)-Pt(l)-Ru(l) Ru(S)-Pt(l)-Pt(2) Ru(S)-Pt( I)-Ru(3) Ru(S)-Pt( 1)-Ru(6) Ru(l)-Pt(l)-Pt(2) Ru(l)-Pt( 1)-Ru(6) Ru(l)-Pt(l)-Ru(2) Ru(3)-Pt( l)-Ru(6) Ru(3)-Pt( 1)-Ru(2) Ru(2)-Pt(2)-Ru(3) Pt(l)-Pt(Z)-Ru(4) Ru(4)-Pt(2)-Ru(6) Ru(3)-Pt(2)-Ru(6) Ru(l)-Pt(3)-Ru(4) Ru( l)-Pt(3)-Ru(5) Ru(l)-Pt(3)-Ru(2) Ru(4)-Pt(3)-Ru( 5) Ru(3)-Pt(3)-Ru(5) Ru(3)-Pt(3)-Ru(2) Pt(2)-Ru(2)-Pt(3) Pt(Z)-Ru(2)-Ru(5)

71.70(5) 118.75(5) 109.73(6) 92.87(5) 120.52(5) 163.66(5) 108.23(5) 122.80(5) 86.03(5) 90.62(5) 96.57(4) 122.61(5) 119.93(5) 122.96(5) 7 1.18(5) 113.41(6) 122.61(5) 107.18(5) 88.41(5) 90.20(5) 110.53(6)

R u ( ~ ) - R u ( ~ ) - R u ( ~ )122.25(7) R u ( ~ ) - R u ( ~ ) - R u ( ~ )113.25(7) Ru(.Q)-Ru(2)-Pt( 1) 90.51 (6) Ru(6)-Ru(2)-Pt(3) 123.8l(5) R u ( ~ ) - R u ( ~ ) - R u ( ~ ) 86.96(6) Pt(l)-R~(3)-Pt(3) 70.24(4) Pt(l)-Ru(3)-Ru(4) 94.80(6) Pt(3)-Ru(3)-Pt(2) 90.41(5) Ru(l)-Ru(3)-Pt(2) 117.35(5) Ru(l)-Ru(3)-Ru(4) 116.39(7) Pt(3)-Ru(4)-Pt(2) 91.99(5) R u ( ~ ) - R u ( ~ ) - R u ( ~ ) 88.32(6) Pt( l)-Ru(5)-Pt(3) 7 1.32(4) Pt(3)-R~(l)-Pt(l) 71.50(4) 0(63)-C(63)-Ru(6) 150(2) 0(63)-C(63)-Pt(l) 125(2) 0(22)-C(22)-R~( 2) 15l(2) 0(22)4(22)-Ru(4) 129(2) Ru(2)-C(22)-Ru(4) 80.6(7) Ru(6)-C(63)-Pt(l) 84.1(8) M-C(av)-0 177(2)

@Anglesare in degrees. Estimated standard deviations in the least significant figure are given in parentheses.

acetate/heptane (1/1) by cooling to 10 "C. All data crystals were mounted in thin-walled glass capillaries. Diffraction measurementa were made on a Rigaku AFC6S fully automated fourcircle diffractometer by using graphite-monochromated Mo K a radiation. Unit cells were determined and refined from 15 randomly selected reflections obtained by using the AFC6 automatic search, center, index, and least-squares routines. All data processing was performed on a Digital Equipment Corp. VAXstation 3520 computer by using the TEXSAN structure solving program library (version 5.0) obtained from Molecular Structure Corp., The Woodlands, TX. Neutral atom scattering factors were calculated by the standard procedures.s" Anomalous dispersion corrections were applied to all non-hydrogen atoms.sb Lorentz/polarization (Lp) and absorption corrections were applied to the data for each structure. Full-matrix least-squares refinements minimized the function: where w = l/u(FOp,d F 0 ) = u(Fo2)/2FO, and a(FO2) = [u(Zraw)* + (0.021,,t)211/*/L,. All of the structures were solved by a combination of direct methods (MITHRIL) and difference Fourier analyses. The (8) (a) International Tables for X-ray Crystallography; Kynoch Press: Birmingham, England, 1975;Vol. IV, Table 2.2B, p 99. (b) Ibid. Table 2.3.1, p 149.

c i i 3j C(20) C(21) C(22) C(23) C(31)

0.16039(02) 0.28702(02) 0.15705(05) 0.28743(05) 0.12867(05) 0.19006(05) -0.0084(05) 0.0820(05) 0.2178(05) -0.0108(05) 0.4156(05) 0.2230(05) 0.3 170(05) 0.4603(05) 0.0456(05) -0.03 17(05) 0.1421(05) 0.2848(05) 0.0756(06) 0.0783(06) 0.2336(05) 0.2890(05) 0.3028(06) 0.2381(05) 0.0565(07) 0.1127(06) 0.1958(06) 0.0534(07) 0.3716(06) 0.2412(07) 0.3078(06) 0.3952(07) 0.0758(07) 0.0288(07) 0.1 391 (06) 0.2482(07) 0.1 193(07) 0.1203(07)

0.12226(04) 0.22866(04) 0.19828(08) -0.03619(08) -0.05076(08) 0.35474(08) 0.1072(09) 0.2145(08) 0.4630(07) 0.2701(08) 0.4200(08) -0.1535(07) -0.3014(08) -0.0236(08) -0.1930(08) -0.0064(07) -0.2938(08) 0.5897(08) 0.4049(09) 0.5110(09) 0.0222(09) 0.1 195(09) 0.2408(09) 0.1796(09) 0.1055( 11) 0.201 3( 10) 0.3651(11) 0.2406( 10) 0.3447( 11) -0.0975( 10) -0.201 7( 12) -0.0230( 10) -0.1368(10) -0.0179(10) -0.2026( 11) 0.5026( 12) 0.3845(11) 0.4468(11)

0.912186( 16) 0.874960( 16) 0.79573(03) 0.87000(03) 0.82771(03) 0.94879(03) 0.9574(03) 0.6793(03) 0.7790(03) 0.8337(03) 0.8444(03) 0.9738(03) 0.8343(03) 0.9214(04) 0.9190(03) 0.7644(03) 0.7642(03) 0.9763(04) 1.0434(04) 0.87 12(03) 0.7 832( 04) 0.8000(04) 0.9609(04) 0.9826(04) 0.9420(04) 0.7221(05) 0.7870(04) 0.8222(04) 0.8565(04) 0.9352(05) 0.847 l(04) 0.9013(04) 0.8863(05) 0.7891(04) 0.7881(04) 0.9667(05) 1.0076(05) 0.8977(05)

2.27(2) 2.12( 2) 2.22(4) 2.34(4) 2.37(4) 2.71(4) 6.3(5) 5.6(5) 4.6(4) 5.0(5) 5.4(5) 5.1(5) 5.2(5) 6.0(5) 6.1(5) 4.8(4) 4.9(5) 6.1(5) 7.4(6) 7.0(6) 2.6(5) 2.1(5) 2.8(5) 2.3(5) 3.7(6) 3.3(6) 3.1(6) 3.3(6) 3.0(6) 3.7(6) 3.3(6) 3.2(6) 3.6(6) 3.2(6) 3.0(6) 4.0(7) 4.2(6) 4.1(6)

positions of the hydrogen atoms in all of the structures were calculated by assuming idealizedgeometries. Their contributions were added to the structure factor calculations,but their positions were not refined. Crystal data and results of the analyses are listed in Table I. Compounds 2, 3, and 5 crystallized in the triclinic crystal system. The space group Pi was assumed and confirmed by the successful solution and refinement of the structure in each case. For compounds 2 and 5, all non-hydrogen atoms in the structures were refined with anisotropical thermal parameters. For 3, only the metal atoms were refined anisotropically. For 3,1.5 molecules of hexane from the crystallization solvent were found cocrystallized in the lattice in the final stages of the analysis. These were included in the analysis and were satisfactorily refined. Compound 4 crystallized in a monoclinic crystal system. From /c the systematic absences in the data the space group R ~ was uniquely identified. All non-hydrogen atoms in this structure were refined anisotropically. Compound 6 crystallized in the orthorhombic crystal system. The space group Pbcn was established on the basis of the systematic absences observed during the collection of data. All non-hydrogen atoms were refined with the anisotropical thermal parameters. In the final stages of the analysis, 1 molecule of ethyl acetate and 0.5molecule of heptane cocrystallized from the crystallization solvent were found in the lattice. The heptane molecule was position about a crystallographic 2-fold rotation axis. These molecules did not define to a convergence and were included as fixed contributions on the final cycles of least-squares refinement.

Results and Discussion

Two new compounds,PtzRus(C0)8(~13-11~-PhCzPh)2(~lqv2-PhC2Ph) (2) (6%) and P~~RU~(CO)~~(CL~'?~-P~CZ

A d a m and Wu

1252 Organometallics, Vol. 12,No. 4,1993 Table IX. Intramolecular Distancess for 4 Pt(l)-Pt(2) Pt( l)-Ru( 1) Pt( l)-Ru(2) Pt( l)-Ru(3) Pt( l)-Ru(4) Pt( 1)-C(4) Pt(Z)-Ru( 1) Pt (~ ) - R u 2) ( Pt(2)-R~(4) Pt (2)-C( 2) Pt(2)-C(3) Ru(l)-Ru(3)

2.5325(6) 2.9100(9) 2.8727(9) 2.7937(9) 2.685(1) 2.199(9) 2.8671(9) 2.840( 1) 2.7395(9) 2.145 (9) 2.08 l(9) 2.816(1)

Ru(1)-C( 1) Ru(l)-C(2) Ru(2)-Ru(3) Ru(2)-C(l) Ru(2)-C(2) Ru(3)-C( 1) Ru(4)-C(3) RU(4)-C (4) C(l)-C(2) C(3)-C(4) M-C(av) C-O(av)

2.29(1) 2.322(9) 2.792(1) 2.343(9) 2.367(9) 2.17(1) 2.23( 1) 2.19( 1) 1.44( 1) 1.35(1) 1.90( 1) 1.14(1)

0 Distances are in angstroms. Estimated standard deviations in the least significant figure are given in parentheses.

Table X. Intramolecular Bond Angless for 4 Pt(2)-Pt( l)-Ru(l) 63.13(2) Pt( 2)-Pt ( l)-Ru( 2) 63.03 (2) Pt(2)-Pt( 1)-R~(3) 101.15(2) Pt(Z)-Pt(l)-Ru(4) 63.27(2) Ru(l)-Pt(l)-Ru(2) 80.70(3) Ru(l)-Pt( 1)-R~(3) 59.12(3) Ru(l)-Pt( l)-Ru(4) 93.27(3) Ru(2)-Pt(l)-Ru(3) 59.03(2) Ru(2)-Pt(l)-Ru(4) 122.21(3) Ru(3)-Pt( 1)-R~(4) 152.35(3) Pt(l)-Pt(Z)-Ru(l) 64.88(2) 64.35(2) Pt ( 1)-Pt( 2)-R~(2) 6 1.08(2) Pt( l)-Pt(2)-Ru(4) Ru( 1)-Pt (2)-Ru( 2) 8 1.99(3)

Ru(l)-Pt(2)-Ru(4) 93.07(3) Ru(2)-Pt(2)-Ru(4) 121.41(2) Pt( l)-Ru( 1)-Pt(2) 51.99(2) Pt(l)-Ru(l)-Ru(3) 58.38(2) Pt(Z)-Ru(l)-Ru(3) 92.86(3) Pt(l)-R~(2)-Pt(2) 52.62(2) Pt(l)-Ru(2)-Ru(3) 59.07(2) Pt(2)-Ru(2)-Ru(3) 93.94(3) Pt(l)-Ru(3)-Ru(l) 62.50(3) Pt(l)-Ru(3)-Ru(2) 61.90(2) R u ( ~ ) - R u ( ~ ) - R u ( ~ ) 83.77(3) Pt( 1)-Ru(4)-Pt (2) 55.65(2) Ru(2)-C(2 1)-0(2 1) 167( 1) M-C(av)-0 175(1)

Figure 1. An ORTEP drawing of PtzR~3(C0)8(r3-1~-PhC2Ph)z(~4-+PhC2Ph)(2) showing 50% probability thermal ellipsoids.

Angles are in degrees. Estimated standard deviations in the least significant figure are given in parentheses. (1

(3) (27%), were obtained from the reaction of 1 with diphenylacetylene in refluxing heptane (97 "C). Both products were characterized by IR, lH NMR, and singlecrystal X-ray diffraction analyses. An ORTEP diagram of molecular structure of 2 is shown in Figure 1. Selected final atomic positional parameters are listed in Table 11. Selected interatomic bond distances and angles are listed in Tables I11 and IV. The molecule contains a cluster of two platinum and three ruthenium atoms in the form of a distorted square pyramid. Similar structures were observed for the complexes NizRu3(C0)&pz(p4-q2-PhCzPh) (819 and AUZRU~(CO)~(COM~)(PP~~ZH (9).l0 The platinum atoms in 2 are located in the apical position, Pt(l),and one of the basalpositions,Pt(2). In compounds 8 and 9, the heteronuclear pair of metal atoms are both located in basal positions. A similar pattern was also observed in the heteronuclear carbido cluster complexes M2Fe3(C0)14(C)(M = Co or Rh)ll 10.

Figure 2. An ORTEP diagram of Pt3R~(CO)14(p3-q2-PhC~Ph)3 (3) showing 50% probability thermal ellipsoids.

The metal-metal bond distances in 2 range from 2.666(1)AforPt(2)-Ru(3) to2.9369(9)A for Pt(l)-Pt(2). These distances are not unusual.lZ Each ruthenium atom contains two carbonyl ligands while each platinum atom only has one. One of the eight carbonyl ligands, C(32)-0(32) is a slight asymmetrical bridge, Ru(2).4(32) = 2.58(1) A,

Ru(3)-C(32)-(32) = 162.4(9)O. There are three PhCzPh ligands in this complex. Two of these are triply bridging and adopt the usual ~(3-11mode: one is on the PhRu triangle Pt(l),Pt(2), Ru(3) and one is on the PtRuz triangle PtW, Ru(l), Ru(2). The third PhCzPh ligand is a quadruple bridge spanning the base of the square pyramid. Compound 8 contains a similar quadruply bridging alkyne ligand.g The four basal metal atoms of 2 do not lie in a perfect plane. Their deviation from the mean plane is Pt(2) -0.05, Ru(1) +0.19, Ru(2) -0.18, and Pt(3) +0.19 A. The similar pattern was also observed in the structure of the complex O~s(C0)1,(p4-1~-HC2Et).~~ Compound 2 contains total of 72 electrons which is two less than the 74 expected for a square-pyramidal ~1uster.l~ Previous studies have shown that clusters containing diplatinum groups often contain two fewer electrons than predicted by the conventional electron counting theories.lS An ORTEP drawing of molecular structure of 3 is shown in Figure 2. Selected final atomic positional parameters are listed in Table V. Selected interatomic bond distances

(9) Tiripicchio, A.; Tiripicchio-Camellini, M.; Sappa, E. J. Chem. Soc., Dalton Trans. 1984, 627. (10) Farrugia, L. J.; Freeman, M. J.; Green, M.; Orpen, A. G.; Stone, F. G. A.; Salter, I. D. J. Organomet. Chem. 1983, 249, 273. (11)(a) Hriljac, J. A.; Holt, E. M.; Shriver, D. F. Inorg. Chem. 1987, 26, 2943. (b) Gubin, S. P. Pure Appl. Chem. 1986,58, 567. (12) Farrugia, L. J. Adu. Organomet. Chem. 1990, 31, 301.

(13) Gomea-Sal, M. P.; Johnson, B. F. G.; Kamarudin, R. A,; Lewis, J.; Raithby, P. R. J. Chem. Soc., Chem. Commun. 1985, 1622. (14) Mingos, D. M. P.; May, A. S. In The Chemistry of Metal Cluster Complexes; Shriver, D. F.; Kaesz, H. D.; Adams, R. D., Eds.; VCH Publishers: New York, 1990; Chapter 2. (15) Evans, D. G.; Mingos, D. M. P. J. Organomet. Chem. 1982,240, 321.

(2)

(8)

(9)

(10)

Cluster Synthesis

Organometallics, Vol. 12, No. 4, 1993 1253 Table XI. Positional Parameters and B(eq) Values for P ~ & ~ ( C ~ ) I ~ ( C 5Z P ~ Z ) ~ atom

X

Pt(1) 0.35182(06) Pt(2) 0.21483(06) Pt(3) 0.19885(06) Ru(1) 0.33828(12) Ru(2) 0.46113(13) Ru(3) 0.38522(12) Ru(4) 0.26241(12) Ru(5) 0.13138( 12) Ru(6) 0.03992(12) O(11) 0.1810(12) O(12) 0.3756(13) O(13) 0.2832(11) O(21) 0.3827(12) O(22) 0.5719(14) Figure 3. An ORTEP drawing of P ~ Z R U ~ ( C O ) ~ ~ ( P ~ - O(23) ~ ~ ~ - P0.6284(12) ~C~O(31) 0.5062(13) Ph)(p+PhCzPh) (4) showing 50% probability thermal O(32) 0.4740(12) ellipsoids. O(33) 0.5413(11) O(41) 0.0940(13) O(42) 0.3753(14) O(43) 0.2217(11) O(51) 0.0070(13) O(52) 0.2838(12) O(53) 0.1808(14) O(61) -0.1631(14) O(62) 0.0254(11) O(63) 0.0381(11) C(l) 0.4849(14) C(2) 0.4268(14) C(3) 0.2676(14) C(4) 0.2471(14) C(5) 0.0341(14) C(6) 0.0702(14) C(11) 0.2359(17) C(12) 0.3602(17) C(13) 0.3033(19) C(21) 0.4091(16) C(22) 0.5290(18) C(23) 0.5627(18) Figure 4. An ORTEP diagram of P ~ ~ R u ~ ( C O ) ~ ~ ( ~ L ~ - ? C(31) ~ - P ~ C 0.4566(17) ZC(32) 0.4361(17) Ph)3 (5) showing 50% probability thermal ellipsoids. C(33) 0.4734(18) C(41) 0.1566(19) and angles are listed in Tables VI and VII. The cluster C(42) 0.3326(17) contains three platinum and six ruthenium atoms and can C(43) 0.2444(16) C(51) 0.0538(16) be described as a tricapped octahedron Ru(2), Ru(3), RuC(52) 0.2317(16) (4), Pt(l), Pt(2), Pt(3) containing a bond between the C(53) 0.1645(17) capping atoms Ru(1) and Ru(5). This appears to be a new C(61) -0.0860(17) structural type for nine metal cluster ~omp1exes.l~ With C(62) 0.0322(16) 22 metal-metal bonds, 18-electron configurations can be C(63) 0.0547(16)

assigned to each metal atom although two of the metalmetal bonds must be viewed formally as donorlacceptor bonds, Pt(1) Ru(5) and Ru(3) Pt(2). Two of the metal-metal bonds in 3 are unusually long, Ru(l)-Ru(5) = 3.125(2) A and Pt(l)-Pt(3) = 3.124(1) A, but bonds of similar lengths have been observed in other platinum,16 ruthenium,17and platinum-ruthenium18 cluster complexes. Compound 3 contains three ~ 3 - 1 1PhCzPh ligands that occupy PtRu, triangular groupings. It is worth pointing out that for two of the three PhCzPh ligands, the acetylenic C-C bond is not completely parallel to one of the three metal-metal bonds of the PtRuz triangle as usually observed for p3-I( ligands. The angles between these acetylenic C-C vectors and the closest metal-metal vectors

-

-

(16) Calabrese, J. C.; Dahl, L. F.; Chini, P.; Longoni, G.; Martinengo, S. J. Am. Chem. SOC.1974,96, 2614. (17) Adams, R. D.; Chen, G.; Tanner, J. T.; Yin, J. Organometallics 1990,9, 1240. (18) (a) Davies, D. L.; Jeffery, J. C.; Miguel, D.; Sherwood, P.; Stone, F. G. A. J . Chem. Soc., Chem. Commun. 1987, 454. (b) Davies, D. L.; Jeffery, J. C.; Miguel, D.; Sherwood, P.; Stone, F. G. A. J. Organomet. Chem. 1990,383,463.

Y

Z

0.20276(05) 0.24105(05) 0.24509(05) 0.23147(11) 0.333 17( 10) 0.23328( 11) 0.09735( 10) 0.35700(11) 0.20037(11) 0.0860( 10) 0.2309(11) 0.3908( 11) 0.4737(10) 0.4436( 11) 0.3520(10) 0.2379(10) 0.41 18(10) 0.1760( 10) -0.0125(11) -O.0237(11) 0.0160(09) 0.4326( 12) 0.4321 (09) 0.5039( 12) 0.1615( 12) 0.0272( 11) 0.1590(10) 0.2303( 12) 0.1670(13) 0.1590( 13) 0.2357(11) 0.3075(13) 0.2521 (1 3) 0.138 5(16) 0.2302(14) 0.3302( 15) 0.4203( 14) 0.401 7( 14) 0.3442( 13) 0.2345( 14) 0.3467( 16) 0.1955(15) 0.0320( 15) 0.0227( 15) 0.0536( 14) 0.4053(15) 0.3936( 14) 0.4483(15) 0.178 1(1 5) 0.0937( 16) 0.1801 (1 3)

0.87949(06) 0.9998 l(06) 0.80339(06) 0.68993(12) 0.83303( 12) 1.09103( 12) 0.99361 (1 2) 0.94099( 12) 0.88561 (1 2) 0.5984(11) 0.4743( 13) 0.7044(11) 0.9464( 12) 0.7223(13) 0.9806( 13) 1.2756(14) 1.1387( 12) 0.9807(11) 1.0350( 13) 1.0196( 12) 0.7645( 1 1) 1.0776( 14) 1.1160(12) 0.8638(15) 0.8903( 14) 0.7738( 13) 1.0927(12) 0.7395( 14) 0.7619( 13) 1.1432(14) 1.1446(14) 0.8 171(1 5) 0.7546( 14) 0.6338(15) 0.5564(18) 0.7 161(19) 0.9078( 17) 0.7640(17) 0.9261 (17) 1.2055(17) 1.1178(16) 1.0060( 16) 1.0170(17) 1.0123( 16) 0.8478(18) 1.0221( 17) 1.0518( 18) 0.8924(18) 0.8875(17) 0.8 163(15) 1.0170( 18)

B(eq), A2

are 12.8' for C(3)-C(4) vs Pt(l)-Ru(5) and 9.0' for C(1)C(2) vs Pt(2)-Ru(4), respectively. This distortion is probably due to steric effects. There are 14 carbonyl ligands, and two of them are bridges across the Ru(2)Ru(4) and Pt(l)-Ru(6) bonds. When compound 3 was treated with carbon monoxide (1atm) at 25 'Cy three products, PtzRu4(CO)14(p3-?2-PhCzPh)(p4-v2-PhCzPh)(4,16%) , P ~ ~ R u ~ ( C O ) ~ ~ ( P ~ - ~ ~ - P ~ (5,20%), and a partially characterized compound X,were isolated. Compounds 4 and 5 were characterized by IR, lH NMR, and single-crystal X-ray diffraction analyses. An ORTEP diagram of molecular structure of 4 is shown in Figure 3. Selected final atomic positional parameters are listed in Table VIII. Selected interatomic bond distances and angles are listed in Tables IX and X. Compound 4 contains six metal atoms. Five, the two platinum and three ruthenium atoms, are arranged in the form of a square pyramid as found in 2. The fourth ruthenium atom bridges the Pt-Pt edge of the square pyramid. The Pt-Pt bond distance in 4 is significantly

Adams and Wu

1254 Organometallics, Vol. 12, No. 4,1993 Table XII. Intramolecular Distancesa for 5 Pt( 1)-Pt( 2) Pt( 1)-Pt(3) Pt(1)-Ru(1) Pt(l)-R~(2) Pt(l)-Ru(3) Pt(l)-Ru(4) Pt( 1)-C( 2) Pt(1)-C(33) Pt( 1)-c(43) Pt(2)-Pt(3) Pt(2)-C(52) Pt(2)-Ru(3) Pt(2)-Ru(4) Pt(2)-R~(5) Pt( 2)-Ru( 6) Pt (2)-C (4) Pt(2)-C(63) Pt(3)-Ru( 1) Pt(3)-Ru(2) Pt(3)-Ru(5)

2.774(1) 2.736(1) 2.734(2) 2.756(2) 2.806(2) 2.852(2) 2.06(2) 2.46(2) 2.72(2) 2.685(1) 2.57(2) 2.795(2) 2.724(2) 2.799(2) 2.83 5(2) 2.03(2) 2.47(2) 2.670(2) 3.877(2) 2.778(2)

Pt(3)-Ru(6) Pt(3)-C(6) Pt(3)-C(13) Ru( l)-Ru(2) Ru(1)-C(1) Ru(l)-C(2) Ru(2)-C( 1) Ru(3)-Ru(4) Ru(3)-C(3) Ru(3)-C(4) Ru(4)-C(3) Ru(5)-Ru(6) Ru(5)-C(5) Ru(6)-C(5) Ru(6)-C(6) C(l)-C(2) C(3)-C(4) C(5)-C(6) Ru-C(av) 0-C(av)

2.726(2) 2.02(2) 2.48(3) 2.675(3) 2.25(2) 2.20(2) 2.07(2) 2.733(3) 2.22(2) 2.22(2) 2.08(2) 2.742(3) 2.07(2) 2.28(2) 2.20(2) 1.37(3) 1.43(3) 1.36(3) 1.89(3) 1.15(3)

Distances are in angstroms. Estimated standard deviations in the least significant figure are given in parentheses.

Table XIII. Intramolecular Bond Angles. for 5 Pt(2)-Pt( 1)-Pt(3) Pt(2)-Pt(l)-Ru( 1) Pt(Z)-Pt(l)-Ru(2) Pt(2)-Pt( l)-Ru(3) Pt(Z)-Pt(l)-Ru(4) Pt(3)-Pt( l)-Ru(l) Pt(3)-Pt( l)-Ru(2) Pt(3)-Pt( l)-Ru(3) Pt (3)-Pt( 1)-Ru(4) Ru( 1)-Pt( l)-Ru(2) Ru(l)-Pt(l)-R~(3) Ru(l)-Pt(l)-Ru(4) Ru(Z)-Pt(l)-Ru(3) Ru(2)-Pt( 1)-R~(4) Ru(3)-Pt(l)-Ru(4) Pt(l)-Pt(2)-Pt(3) Pt(l)-Pt(2)-R~(3) Pt( l)-Pt(2)-Ru(4) Pt( I)-Pt(2)-Ru(5) Pt(l)-Pt(2)-Ru(6) Pt( 3)-Pt(2)-R~(3) Pt(3)-Pt(2)-Ru(4) Pt(3)-Pt(2)-Ru(5) Pt(3)-Pt(2)-Ru(6) Ru(3)-Pt(2)-Ru(4) Ru(3)-Pt(2)-R~(5) Ru( I)-C( 13)-O(13) R~(3)-C(33)-0(33) R~(4)-C(43)-0(43) R~(5)-C(52)-0(52) R~(6)-C(63)-0(63) Ru-C (av)-0

58.3 l(3) 116.12(5) 113.80(5) 60.1 l(4) 57.90(4) 58.43(4) 89.79(5) 116.99(5) 98.05 (5) 58.3 l(6) 159.34(6) 140.10(6) 103.21(6) 160.94(6) 57.76(5) 60.13(3) 60.51(4) 62.48(4) 112.20(5) 111.43(5) 119.13(5) 102.54(5) 60.8 l(4) 59.12(4) 59.35(6) 137.55(6) 162(2) 161(2) 167(2) 163(2) 161(2) 177(2)

Ru(3)-Pt(2)-Ru(6). . Ru(4)-Pt(2)-Ru(5) Ru(4)-Pt(Z)-Ru(6) Ru(S)-Pt(Z)-Ru(6) Pt(l)-Pt(3)-Pt(2) Pt(l)-Pt(3)-Ru( 1) Pt( l)-Pt(3)-Ru(5) Pt(l)-Pt(3)-Ru(6) Pt (2)-Pt( 3)-Ru( 1) Pt(2)-Pt(3)-R~(5) Pt(2)-Pt(3)-Ru(6) Ru(l)-Pt(3)-Ru(5) Ru(l)-Pt(3)-Ru(6) Ru(5)-Pt(3)-Ru(6) Pt(l)-R~(l)-Pt(3) Pt(l)-Ru(l)-Ru(2) Pt(3)-Ru(l)-Ru(2) Pt( l)-Ru(3)-Pt(2) Pt(l)-Ru(3)-Ru(4) Pt(2)-Ru(3)-Ru(4) Pt(2)-Ru(5)-Pt(3) Pt(2)-Ru(5)-Ru(6) Pt(3)-Ru(5)-Ru(6) Pt(2)-Ru(6)-Pt(3) Pt(2)-Ru(6)-Ru(5) Pt(3)-Ru(6)-Ru(5)

163.13(6) 159.58(6) 103.95(6) 58.24(6) 61.56(3) 60.75(4) 114.08(5) 116.10(5) 121.61(5) 61.63(5) 63.19(5) 141.5 l(7) 158.74(6) 59.75 (6) 60.82(4) 61.26(6) 92.98(7) 59.38 (4) 61.96(5) 59.03(6) 57.56(4) 6 1.53(6) 59.19(6) 57.70(4) 60.23(6) 61.05(6)

Angles are in degrees. Estimated standard deviations in the least significant figure are given in parentheses.

Figure 5. An ORTEP diagram of PtRuz(CO)s(113-r12-PhCzPh)(dppe) (6) showing 50 % probability thermal ellipsoids. Selectedinteratomic distances (A) and angles (deg) for 6 are: Pt-Ru(1) = 2.766(1), Pt-Ru(2) = 2.684(1), Ru(l)-Ru(2) = 2.725(1), Pt-P(l) = 2.308(4), Pt-P(2) = 2.277(4), Pt-C(1) = 2.09(1), Ru(l)-C(l)= 2.56(1), Ru(2)-C(l) = 2.03(1), Ru(2)C(1) = 2.19(1), Ru(2)-C(2) = 2.23(1), C(l)-C(2) = 1.38(2); Pt-Ru(l)-Ru(P) = 58.52(4),Pt-Ru(B)-Ru(l) = 61.50(4),RU(l)-Pt-Ru( 2) = 59.99(4).

Table XIV. Positional Parameters and B(eq) Values for PtRuz(CO)dPwzPh) (dpw), 6 atom X Y z B(eaL A2 0.72367(03) 0.72061(06) 0.75204(06) 0.79490( 18) 0.68823( 18) 0.8169(07) 0.6341(06) 0.7654(06) 0.7698(06) 0.8765(06) 0.7629(06) 0.6673(06) 0.669 3(06) 0.7845(07) 0.75 13(07) 0.7825(09) 0.6663(09) 0.7477(07) 0.7625(08) 0.8296(09) 0.7589(07)

0.06257(03) -0.03831(05) -0.04772(05) 0.13244(19) 0.13804(17) 0.0346(07) -0).0460(06) -0.1622(05) -0.0067(07) -0.04 16(06) -4l.1841(06) -0.0083(06) -0.065 l(07) 0.2007(07) 0.1835(06) 0.0073(08) -0.0383(07) -0.1 146(08) -0.02 16(07) -0.0417(07) 4.1329(08)

0.02464(03) -0.05560(06) 0.071 1 l(O6) 0.0497(02) -0.03980(20) -0.1252(08) -0.1654(07) -0.0884(06) 0.2104(06) 0.0210(08) 0.1006(07) 0.0482(07) 0.0191 (07) -0.001 8(08) -0.0642(08) -0.0997(09) -0.1243(09) -0.0766(08) 0.1578( 10) 0.0406(09) 0.0896(08)

3.22(3) 3.76( 6) 3.53(6) 4.1(2) 3.7(2) 10(1) 7.9(9) 7.3(8) 8.0(9) 8.0(9) 8.2(9) 3.2(8) 3.4(7) 5(1) 4.4(8) 6(1) 5 ~ ) 5(1) 6(1) 6(1) 5(1)

(I

shorter than that in 2,2.5325(6) vs 2.9396(9) A. This may be due to the presence of the bridging ruthenium atom. All other metal-metal bond distances in 4 are similar to those in 2. There are total 14 terminal carbonyl ligands. Each ruthenium atom has three, and each platinum atom has one. In addition to the quadruply bridging PhCzPh ligand, there is one triply bridging PhCzPh ligand on the PtzRu triangle Pt(l), Pt(2),Ru(4). Compound 4 contains 88valence electrons which is exactly the number predicted for an edge-bridged square-pyramidal structure.14 An ORTEP of diagram of molecular structure of 5 is shown in Figure 4. Selected final atomic positional parameters are listed in Table XI. Selected interatomic bond distances and angles are listed in Tables XI1 and XIII. To a first approximation the structure of 5 can be

viewed as a combination of three M4 tetrahedra. Two of these are closed tetrahedra: Pt(l), Pt(2), Ru(3), Ru(4) and Pt(2), Pt(3), Ru(5), Ru(6). The third, Pt(l), Pt(3), Ru(l), Ru(2), is a “butterfly” tetrahedron. The three tetrahedra are joined via the platinum atoms which form a triangle in the center of the cluster. This is another new structural type for nine-metal ~1usters.l~ All metal-metal bond distances in 5 are similar to those found in 1-4. The long distance between Pt(3) and Ru(2), 3.877(2) A, indicates that there is no bonding interaction between these two metal atoms. In compound 5 there are 18 carbonyl ligands: two are semibridging ligands, Pt(3)--C(13) = 2.48(3) A and Pt(l).-C(33) = 2.46(2) A. The three PhCzPh ligands bridge the three PtRu2 triangles: Pt(l), Ru(l), Ru(2); Pt(2); Ru(3), Ru(4); and Pt(3), R u ( ~ )RU, (6). In this way, the molecule of 5 appears to have an approximate C3 axis that is perpendicular to the Pt3

Clwter Synthesis

Organometallics, Vol. 12, No. 4, 1993 1255

Scheme I

triangle and passes through ita center. It is apparent that compound 5 is an assembly of three PtRup(p3-a4-PhCpPh) groupings that are linked through the platinum atoms. Compound 5 contains total 126 valence electrons, which is two less than that expected for a condensed polyhedron of this type. This could be remedied by the formation of a metal-metal bond between Pt(3) and Ru(2), but this has not happened. Thus, platinum atom, Pt(3), is left with a 16-electron configuration. We suspected that 5 could be split into three trinuclear PtRup(p3-q2-PhCpPh)cluster complexes by ligand addition, and this was achieved by treatment of 5 with dppe in a hexane solution at 25 OC. The new compound 6, PtRu2(CO)&3-a2-PhCpPh)(dppe),was obtained in a 10% yield. When 5 was treated with CO followed by an addition of dppe, compound 6 was obtained in much better yield (46%). When treated with CO (1atm) in the absence of dppe, there was evidence of the formation of a new compound detected by IR spectroscopy that was only stable under a CO atmosphere. When the CO atmosphere was removed, it decomposed and compounds 2 (40%) and 4 (10%)were formed. We suspect that this species is the complex PtRup(CO)s(p3-a2-PhC2Ph) (7) formed by the fragmentation of 5. When the reaction was performed in the presence of dppe, the complex 6 was formed which we feel is simply a more stable derivative of 7. We found that the complex 6 could also be obtained in 36% yield from the reaction of PtRuz(CO)s(dppe)with PhCpPh in refluxing heptane solvent. Compound 6 was characterized by single-crystal X-ray diffraction analysis, and an ORTEP of diagram of ita molecular structure is shown in Figure 6. Selected final atomic positional parameters are listed in Table XIV. Compound 6 consists of a triangular cluster with one platinum atom and two ruthenium atoms. The metalmetal bond distances in 6 are similar to those in PtRup-

(CO)s(dppe). The dppe ligand is chelated to the platinum atom. The two Pt-P bond distances in 6, Pt-P(l) = 2.308(4) A and Pt-P(2) = 2.277(4) A, are slightly different, but are similar to those found in PtRuz(CO)s(dppe) and PtR~p(C0)6(dppe)p,~~ The triply bridging PhCpPh ligand does not adopt a perfect p3-11 bond mode. The angle between the acetylenic C-C and the Pt-Ru(1) vectors is 10.7'. Compound 6 contains six linear terminal carbonyl ligands on the ruthenium atoms which are arranged to minimize their steric repulsions. There is a total46 valence electrons in the cluster; thus the platinum atom is believed to have only a 16-electron configuration. As found in PtRup(CO)s(dppe),the platinum atom in 6 has a nonplanar coordination geometry. The dihedral angle between the PtRup and PtPz planes is 58.2'. Although the structure of compound X was not established, some of ita chemical properties were investigated. When treated with CO, X yielded 4 and 5, and when treated with CO followed by an addition of dppe, compound 6 was obtained. Thus, it is believed that compound X is either an isomer of 3 or some species whose number of CO ligands lies between the number in 3 and the number in 5. The results of this study are summarized in Scheme I. The principal product from the reaction of 1with PhCzPh was the nine-metal cluster complex 3. Ita formula suggests that it is a combination of three PtRuz(PhCzPh)groupings. We have shown previously that complex 1 can be split into two PtRup fragments by reaction with dppe. Thus, we believe that 3 was formed by a splitting of 1 into PtRup(PhC2Ph) fragments upon reaction with PhCzPh that followed by a reassembly into 3. The mode of formation of the minor product 2 is not clear at this time. Compound 3 adds 4 equiv of CO under very mild conditions, 1atm/25 'C, to yield 5, which contains a more opened cluster as a result of the metal-metal bond cleavages that accompany the CO addition. Also formed

Adams and Wu

1256 Organometallics, Vol. 12, No. 4, 1993 Scheme I1

-

Dh

'I. rearrangement '\

Ph

+ 4 CO, 25% (3)

was compound 4 whose formula suggests that one of the PtRu2 fragments was eliminated and a product X whose formula has not been unambigously established, but which appears to be a nine-metal cluster similar to 3 and 5 with a different number of CO ligands. It is relatively easy to visualize the formation of compound 5 from 3, see Scheme 11. The addition four carbonyl ligands to 3 induces the cleavage of several metalmetal bonds (dashed lines in Scheme 11). Although several intermediates may be traversed, one could imagine one intermediate A, formed without the cleavage of any metalmetal bonds in the alkyne-bridged PtRu2 triangles. Through cleavage of one Pt-Ru bond and the formation of one Pt-Pt bond, compound 5 would be obtained directly from A. When heated to 68 OC, compound 5 eliminates four CO ligands to reform 3 in an almost quantitative yield. The structure of 5 also suggests a straightforward pathway for cluster assembly from three PtRu2(CO)a(PhCs Ph) groupings. Compound 5 reacted with CO to form a species that was

stable only under a CO atmosphere and that we have formulated as the trinuclear PtRup species 7, Scheme I. When 7 was allowed to decompose in the absence of dppe, significant amounts of 2,4, and X were formed. When the reaction of 5 with CO was performed in the presence of dppe, the compound 6 was obtained. We feel that compound 6 is simply a stabilized form of 7 that was unambiguously characterized through a crystal-structure analysis. The most efficient route to 6 was the reaction of PtRuz(CO)a(dppe) with PhCnPh in refluxing heptane solvent (97O C) .

Acknowledgment. These studies were supported by the National Science Foundation under Grant No. CHE-

8919786. Supplementary Material Available: Tables of phenyl ring and hydrogen atom positionalparameters and hisotropic thermal parameters (35 pages). Ordering information is given on any current masthead page.

OM920693V